532. 
533. 
534, 
of snowmobiling on wildlife include 
noise, destruction of forage and cov- 
ey, compaction of snow, and direct nam 
rassment. 
OFF-ROAD VEHICLES, SKIING, HARASSMENT, 
FORESTS, U.S. STATE PARKS AND LANDS, 
WILDLIFE (GENERAL) 
Youngman, R. £. 1977. 
grebes breeding on rivers. Br. 
70: 544-545. 
Great crested 
Birds 
The author notes that great numbers of 
crested grebes in Britain have in- 
creased markedly, and that as suitable 
breeding habitat on standing water ap~ 
pears to be used up grebes are moving 
to rivers. It is noted that grebes 
appear much more tolerant of boats on 
rivers heavily used for recreation 
than on standing water. 
BOATING, RIVERS, LAKES, FLIGHT DISTANCE , 
GREAT CRESTED GREBE 
Zardus, M. J., and D. J. Parsons. 1980. 
Black bear management in Sequoia and 
Kings Canyon National Parks. Pages 
195-200 in C. J. Martinka and K. L. 
McArthur, eds. Bears--their biology 
Fourth Internationa! 
Conference on Bear Research and Man 
agement, February 19//, Kalispell, 
Mont. Bear Biology Association. 
and management. 
Ready availability of human food 15 
recognized as the cause of black bear- 
human conflicts in 2 National Parks in 
California. The current bear manage- 
ment program seeks to eliminate unnat~ 
ural food sources in an effort to al- 
low bears to lead as natural a life as 
possible. 
CAMPING, HIKING, FORESTS, HUMAN HEALTH 
AND SAFETY, RECREATION MANAGEMENT, WILD 
LTFE MANAGEMENT, U.S. NATIONAL PARKS 
BLACK BEAR 
Zarn, M. 1974 Habitat management ser- 
jes for unique or endangered species, 
report no. 10: Spotted owl Strix 
occidentalis. lI,S, Bur. land Manage 
Tech. Note 242 ?? pp. 
Q7 
R26 
The status, life history, and habitat 
requirements of the spotted owl are 
reviewed. Human disturbance factors 
do not appear to be important for the 
spotted owl, but information is scant 
and the effects of human activities 
have not heen adequately determined. 
Increasing recreational use of moun- 
tain habitats and greater accessibil- 
jty of remote areas through the use of 
off-road vehicles will increase human 
contact with spotted owls and may in- 
troduce additional stress factors. 
HIKING, OFF-ROAD VEHICLES, FORESTS, REC- 
REATION MANAGEMENT, REVIEW, SPOTTED OWL 
Zarn, M. 1974, Habitat management ser- 
ies for unique or endangered species, 
report no. 12: Osprey Pandion haliae- 
tus carolinensis. U.S. Bur. Land Man- 
age lech. Note 254, 41 pp. 
The status, biology, and limiting fac- 
tors of ospreys on public lands are 
described. While ospreys sometimes 
successfully nest in close proximity 
to humans, deliberate harassment and 
shooting are common in some areas. 
Recreationists who carry out their ac- 
tivities close to nesting ospreys may 
keep parent birds off the nest and 
cause losses of eggs and young to ex- 
posure, Management recommendations 
include actions to limit human distur- 
bance of breeding ospreys 
CAMPING, FISHING, HARASSMENT, WILDLIFE 
VIEWING, TOURISM, LAKES, FORESTS, RIV- 
ERS, RECREATTON MANAGEMENT, WILDLIFE 
MANAGEMENT, U.S. BLM LANDS, U.S. NAT ION~- 
Al FORESTS, REVIEW, OSPREY 
1963. Don't feed the bears. 
Parks Mag. 37(189):7-9. 
Zook, M 
Natl 
The author describes incidents of 
property damage and injuries to park 
visitars inflicted by bears and recom 
mends that visitors refrain from feed- 
ing bears or approaching them too 
clasely. 
CAMPING, HIKING, TOURISM, WILDLTFE VIEW- 
ING, FORFSTS, HUMAN HEALTH AND SAFETY, 
THREATENFN AND ENDANGERED SPECIES, U.S. 
NATIONAL PARKS, BLACK BEAR, GRIZZLY BEAR 
